Related: tdf#54053 PDF export: add UNO API to customize the watermark font name

The font name of the watermark text is currently hardwired to Helvetica,
a sans-serif font.

The problem is that this looks bad in case your document uses serif or
monospace fonts. Or perhaps your document uses a single font and you
want to make sure that the watermark uses exactly the same font.

Fix the problem by adding a new "WatermarkFontName" PDF export filter
option to specify the font name explicitly.

Example cmdline usage:

soffice --convert-to pdf:writer_pdf_Export:'{"Watermark":{"type":"string","value":"draft"}, "WatermarkFontName":{"type":"string","value":"Times"}}' test.odt

Change-Id: I2f065e1517236695b0a95369bdcd803125018587
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/143143
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

3 files changed, 58 insertions, 3 deletions

diff --git a/filter/qa/pdf.cxx b/filter/qa/pdf.cxx
index 4c8a9a2dc7dc..c3edb1c5f841 100644
--- a/filter/qa/pdf.cxx
+++ b/filter/qa/pdf.cxx
@@ -196,7 +196,7 @@ CPPUNIT_TEST_FIXTURE(Test, testWatermarkFontHeight)
         return;
     mxComponent.set(loadFromDesktop("private:factory/swriter", "com.sun.star.text.TextDocument"));
 
-    // When exporting that as PDF with a red watermark:
+    // When exporting that as PDF with a 100pt-sized watermark:
     uno::Reference<css::lang::XMultiServiceFactory> xFactory = getMultiServiceFactory();
     uno::Reference<document::XFilter> xFilter(
         xFactory->createInstance("com.sun.star.document.PDFFilter"), uno::UNO_QUERY);
@@ -216,7 +216,7 @@ CPPUNIT_TEST_FIXTURE(Test, testWatermarkFontHeight)
     };
     xFilter->filter(aDescriptor);
 
-    // Then make sure that the watermark color is correct:
+    // Then make sure that the watermark font size is correct:
     std::unique_ptr<vcl::pdf::PDFiumDocument> pPdfDocument
         = pPDFium->openDocument(aStream.GetData(), aStream.GetSize(), OString());
     CPPUNIT_ASSERT(pPdfDocument);
@@ -232,6 +232,51 @@ CPPUNIT_TEST_FIXTURE(Test, testWatermarkFontHeight)
     // i.e. the font size was automatic, could not specify an explicit size.
     CPPUNIT_ASSERT_EQUAL(nExpectedFontSize, nFontSize);
 }
+
+CPPUNIT_TEST_FIXTURE(Test, testWatermarkFontName)
+{
+    // Given an empty Writer document:
+    std::shared_ptr<vcl::pdf::PDFium> pPDFium = vcl::pdf::PDFiumLibrary::get();
+    if (!pPDFium)
+        return;
+    mxComponent.set(loadFromDesktop("private:factory/swriter", "com.sun.star.text.TextDocument"));
+
+    // When exporting that as PDF with a serif watermark:
+    uno::Reference<css::lang::XMultiServiceFactory> xFactory = getMultiServiceFactory();
+    uno::Reference<document::XFilter> xFilter(
+        xFactory->createInstance("com.sun.star.document.PDFFilter"), uno::UNO_QUERY);
+    uno::Reference<document::XExporter> xExporter(xFilter, uno::UNO_QUERY);
+    xExporter->setSourceDocument(mxComponent);
+    SvMemoryStream aStream;
+    uno::Reference<io::XOutputStream> xOutputStream(new utl::OStreamWrapper(aStream));
+    OUString aExpectedFontName("Liberation Serif");
+    uno::Sequence<beans::PropertyValue> aFilterData{
+        comphelper::makePropertyValue("Watermark", OUString("X")),
+        comphelper::makePropertyValue("WatermarkFontName", aExpectedFontName),
+    };
+    uno::Sequence<beans::PropertyValue> aDescriptor{
+        comphelper::makePropertyValue("FilterName", OUString("writer_pdf_Export")),
+        comphelper::makePropertyValue("FilterData", aFilterData),
+        comphelper::makePropertyValue("OutputStream", xOutputStream),
+    };
+    xFilter->filter(aDescriptor);
+
+    // Then make sure that the watermark font name is correct:
+    std::unique_ptr<vcl::pdf::PDFiumDocument> pPdfDocument
+        = pPDFium->openDocument(aStream.GetData(), aStream.GetSize(), OString());
+    CPPUNIT_ASSERT(pPdfDocument);
+    std::unique_ptr<vcl::pdf::PDFiumPage> pPage = pPdfDocument->openPage(0);
+    CPPUNIT_ASSERT_EQUAL(1, pPage->getObjectCount());
+    std::unique_ptr<vcl::pdf::PDFiumPageObject> pPageObject = pPage->getObject(0);
+    CPPUNIT_ASSERT_EQUAL(1, pPageObject->getFormObjectCount());
+    std::unique_ptr<vcl::pdf::PDFiumPageObject> pFormObject = pPageObject->getFormObject(0);
+    OUString aFontName = pFormObject->getFontName();
+    // Without the accompanying fix in place, this test would have failed with:
+    // - Expected: Liberation Serif
+    // - Actual  : Helvetica
+    // i.e. the font name was sans, could not specify an explicit name.
+    CPPUNIT_ASSERT_EQUAL(aExpectedFontName, aFontName);
+}
 }
 
 CPPUNIT_PLUGIN_IMPLEMENT();
diff --git a/filter/source/pdf/pdfexport.cxx b/filter/source/pdf/pdfexport.cxx
index df86ab46393d..5bb6f0baa2fe 100644
--- a/filter/source/pdf/pdfexport.cxx
+++ b/filter/source/pdf/pdfexport.cxx
@@ -109,6 +109,7 @@ PDFExport::PDFExport( const Reference< XComponent >& rxSrcDoc,
 
     mbIsRedactMode              ( false ),
     maWatermarkColor            ( COL_LIGHTGREEN ),
+    maWatermarkFontName         ( "Helvetica" ),
 
     mbHideViewerToolbar         ( false ),
     mbHideViewerMenubar         ( false ),
@@ -576,6 +577,14 @@ bool PDFExport::Export( const OUString& rFile, const Sequence< PropertyValue >&
                         moWatermarkFontHeight = nFontHeight;
                     }
                 }
+                else if (rProp.Name == "WatermarkFontName")
+                {
+                    OUString aFontName{};
+                    if (rProp.Value >>= aFontName)
+                    {
+                        maWatermarkFontName = aFontName;
+                    }
+                }
                 else if ( rProp.Name == "TiledWatermark" )
                     rProp.Value >>= msTiledWatermark;
                 // now all the security related properties...
@@ -1168,7 +1177,7 @@ void PDFExport::ImplExportPage( vcl::PDFWriter& rWriter, vcl::PDFExtOutDevData&
 
 void PDFExport::ImplWriteWatermark( vcl::PDFWriter& rWriter, const Size& rPageSize )
 {
-    vcl::Font aFont( "Helvetica", Size( 0, moWatermarkFontHeight ? *moWatermarkFontHeight : 3*rPageSize.Height()/4 ) );
+    vcl::Font aFont( maWatermarkFontName, Size( 0, moWatermarkFontHeight ? *moWatermarkFontHeight : 3*rPageSize.Height()/4 ) );
     aFont.SetItalic( ITALIC_NONE );
     aFont.SetWidthType( WIDTH_NORMAL );
     aFont.SetWeight( WEIGHT_NORMAL );
diff --git a/filter/source/pdf/pdfexport.hxx b/filter/source/pdf/pdfexport.hxx
index 22f9db1841af..40ac7d3e2f9a 100644
--- a/filter/source/pdf/pdfexport.hxx
+++ b/filter/source/pdf/pdfexport.hxx
@@ -75,6 +75,7 @@ private:
     OUString            msWatermark;
     Color               maWatermarkColor;
     std::optional<sal_Int32> moWatermarkFontHeight;
+    OUString            maWatermarkFontName;
     OUString            msTiledWatermark;
 
     // these variable are here only to have a location in filter/pdf to set the default